Meat is a valuable dietary source of CLA

The conjugated linoleic acids (CLA) represent a group of natural isomers which are derived from linoleic acid. Because of their unique characteristics they exert chemical and physiological effects on the organism which differ from those of linoleic acid. In animal models as well as in in vitro models using tumour cells of human origin, they have been shown to possess anti-carcinogenic characteristics. Fat of animal origin, especially fat from meat and milk products, is the most important dietary source of CLA. Meat of ruminants is a richer source of these compounds than is meat of nonruminant species. Swiss beef contains on an average higher amounts of CLA than American beef. The intake of grass plays an important role since grass favours the production of CLA in the rumen and as a consequence increases their concentration in meat. Variability of CLA concentration can thus be quite high. Provided that the factors which influence tissue concentration will be better known, there is a potential to influence the CLA content of foods of animal origin.